//SORTOUT DD  DSN=C905460.OUTPT,UNIT=3390,SPACE=(CYL,5),
//            DISP=(NEW,CATLG)

DISP

specifies the data set unknown to the operating system (NEW) and catalogs (CATLG) it under the name C905460.OUTPT.

DSNAME

specifies that the data set is called C905460.OUTPT.

SPACE

requests five cylinders of storage for the data set.

UNIT

Indicates that the data set is on a 3390.